An information processing system that searches for information matching given criteria and provides the information to a user is hitherto known. For example, a preference information management system that estimates and uses preference information suitable for a user is disclosed in Patent Literature 1 listed below. The system includes a means for estimating preference information based on the current location and a category of its place when there is no preference information in a certain location, and a means for storing correspondence between absolute location data as represented by latitude and longitude and a category of its place.
Further, a service information delivery device that allows a recipient of service information to easily obtain service information related to the current location is disclosed in Patent Literature 2 listed below. Upon receiving a service delivery request from a terminal of a recipient member, the device automatically acquires the current location information of the terminal, extracts service information matching the service genre desired by the member and also matching the current location information from a delivery file, and delivers the service information to the terminal.
Furthermore, a destination search device for easily conducting a search for a destination even when the name or location of the destination is unknown is disclosed in Patent Literature 3 listed below. The device searches for a destination based on a database storing names, locations and genres of places which can be a destination or relevant place, a selected genre, an input name or genre of a relevant place, and a specified positional relationship.
In such search systems, “Fuzzy” search or “Did you mean” search using a dictionary which defines relations of characters or words is used in some cases. This search technique may be used to estimate a correct word and runs a search when there is a typing error in search criteria. Further, it may be used to estimate another word related to a word input as search criteria and runs a search using the estimated word as well, thereby extending the range of search results.
As a technique relating to a dictionary to implement such a search, a synonym computation device that creates a synonym dictionary reflecting the degree of association of at least two types is disclosed in Patent Literature 4 listed below. The device uses at least two types of degree-of-association dictionaries, and initializes a word group based on one degree-of-association dictionary and merges word groups based on the respective degree-of-association dictionaries, thereby creating a synonym group.